Vossen



Jan. 31, 1956 E. VOSSEN DETECTOR FOR BROKEN STRANDS OF YARN Filed Sept. 8. 1953 H J a 3 lNVENTOR EDWARD VOSSEN S .Q We;

ATTORNEY bodies the following FOR BRGKEN STRANDS F YARN Edward /ossen, Lynbrook, N. Y., assignor to Stop- Motion Bevices Corp, Brooklyn, N. Y.

Application depternher 8, 1953, Serial No. 378,715 8 (Ilaims. (Q1. 2tlll-61.13)

This invention relates to improvements in textile machines and particularly concerns detectors for broken strands of yarn in knitting machines and the like.

Heretofore broken yarn detectors have been employed in knitting machines to stop the machines upon the occurrence of breakage in strands of yarn or thread. These detectors have all been of the gravity operated drop-wise type. Under normal running conditions the thread or yarn would pass through the detector and keep the dropwire upright. When the yarn broke, the drop-wire would fall and make contact with an electrical element to close a suitable relay circuit. The relay would in turn operate to open the power supply to the motor driving the machine to stop the machine. The principal difficulty with the conventional type of gravity operated drop-wise detector is that the drop-wire must necessarily be heavy so that positive electrical contact is made when the wire drops. if the wire is not heavy enough it must be properly weighted. On modern multiplefeed striped cloth knitting machines the detectors of the type mentioned above cannot be used effectively because when certain yarns are idle and slack, the vibration of the machine plus the weight of the drop-wire, causes the drop-wire to fall and stop the machine unnecessarily. On revolving top knitting machines, the centrifugal force generated by the machine whirling around hurls the drop-wire from its upright position causing it to fall and stop the machine unnecessarily. In order to offset the unnecessary falling of the dropwire and stopping of the machine, the expedient has been employed of holding the yarn taut and under tension so that the drop-wire stays up. This has not solved the problem because in most types of knitting the yarn must be kept free from all tension. If yarn is to be held under tension at all it can only be done with certain yarns which are heavy enough to Withstand the tensional force. if tension is employed on yarns in automatic striper machines where a shearing action is used at the yarn feed members, undue tension causes the yarn to pull out of the yarn selecting fingers damaging the work and causing many other dificulties.

The present invention has been devised to overcome all of the above disadvantages and difiiculties. It emdesirabie features:

1. it is small in size so that it can be installed in a limited space.

2. it inc udes electrical contacts which are totally enclosed so that lint and fuzz will not affect its electricai operation and dependability.

3. It loads the yarn so lightly that weak yarns are not broken by its weight.

lit is fast acting so that when yarn breaks, the machine is stopped instantly thereafter.

5. It includes a yarn holder to arrest idle yarns from developing slackness and causing unnecessary stoppage of the machine.

6. It includes a fly-wire instead of a drop-wire so hired grates Patent Q that there is less pull on the yarn, and faster wire movement when the yarn breaks.

7. The fly-wire is held under spring tension so that better and more positive electrical contact is assured.

8. The speed of movement or the fly-wire is adjustable.

9. The assembly includes a yarn holder to prevent slackness in the yarn from unnecessarily stopping the machine. The yarn holder is constructed with an open front end which permits easy threading and cleaning.

The basic and principal object of the invention must be stated to be to provide a broken yarn detector which is more dependable and faster acting than any gravity operated drop-wire type detector heretofore known.

A further object is to provide a fly-wire type detector which depends upon spring tension rather than gravity for its operation.

A further object is to provide a broken yarn detector with a slack yarn holding feature, to prevent unnecessary stoppage of a knitting machine.

Other and further objects and advantages of the invention will become readily apparent from the following detailed description taken together with the drawing wherein:

Fig. 1 is an elevational side view ing the invention.

Fig. 2 is an elevational front view of the device of a device embody- 3 is a sectional view taken on lines 3-3 of Fig. 1. Fig. 4 is a sectional view taken on lines d4 of Fig. 2. Fig. 5 is a plan View of a yarn holding structure forming part of the invention.

Fig. 6 shows a modified form of yarn holder.

Fig. 7 shows an application of the yarn holding structure of Fig. 5 to a gravity operated drop-wire type broken yarn detector.

Fig. 8 is an elevational front view of a detector according to the invention including a modified form of spring tension adjuster.

Fig. 9 is a rear view of the detector spending in part to the view of Pig. 3.

In Figs. 1, 2, 3 and 4 are shown a substantially closed housing formed by a base member 1i; having an open side, and a cover member 11 which fits snugly over the base member to cover the open side. Base member 19 carries a light wire probe 12. Probe 12, is bent at its upper end to form an offset crank portion 13. The crank portion 13 is bent at opposite ends to form two aligned pivot sections 14. 1 which rotate in apertures 16, 17 located in opposite sides of base member it. Pivot sections l4, are spaced from the portion 13, by

disposed parallel to probe two short sections 18,

The sections i 13 are made long enough so that movement of the probe 12 tie lip l9 extending from c side of base member is will ii... rota ion when toe probe is in a horizontal position as shown by position i in Fig. 1.

Probe 12. is located at one side the hous ng is bent at its free end to form a loop 2% and outwardly extending arm 21. The yarn or thread Y to be monitored is passed through the eye of loop shown in Fig. l. The arm 21 serves to facilitate threading of the yarn in the loop and also serves as an indicator when the probe is in the position A to indicate that yarn Y has broken or is disengaged from loop 2%. Attached to crank por 13 is a spring 22 which has an unwound portion passing alongside a guide pin 2 -1 The opposite end of spring is engaged by a loop in the end of lever 25. Lever 25 pivots frictionally on a bolt 26 carried by an apertured slotted wall extension 27 of the base member 1%). Nut 28 is threaded on bolt 25 and may be tightened to adjust the pressure of the Walls of the wall exof Fig. 8 corretension 27 on lever 25. Lever projects beyond wall extension 27 so that it can be positioned by finger pressure on its end as shown by the double headed arrow in Fig. 4 to adjust the tension in spring 22.

An electrical contact element 29 is provided in base member it. it is in the form or" a thin finger extension of the lug which is securely attached to the bottom of base member in by nut 3?. having a head 33 bearing down on lug 1 A pair of insulating washers 34, serve to electrically insulate the contact element 29 from the base member it? and probe 12. Bolt 32 passes through a fairly large aperture in base member it? so there can be no electrical contact between bolt 32 and base member it A metal washer fit; is provided on bolt 32 so that convenient electrical connection can be made from a point between washer 36 and nut 31 to a suitable stop-motion circuit. Another electrical connection for the stop-motion circuit can be made to the wall opening in cover member iii. if desired the electrical connection can be made to any other convenient point on the detector housing since probe 12 is grounded to base member it). A suitable point for such connection would be either one of screws 37, 33 which serve to secure cover member 3 to base mem her it).

An extension is provided in the lower end of cover .iember ll. Extension 2 extends perpendicularly outwards and has an aperture in which is fixed a smooth eyelet 43 through which is threaded the yarn Y.

5 is shown the arrangement of a yarn holder according to the invention. A pair of parallel spring tinge-rs 42, 43 extend parallel outwardly from the detector housing and then are bent inwardly in smooth curves to form an inwardly tapered V-shaped section 44 in which the yarn may be held in a manner to be described. The lingers 42, 43 then flare outwardly at their free ends to provide a means for threading the yarn between the fingers as shown in Fig. l.

in operation, yarn Y is threaded through the fingers 42, i?) of the yarn holder and through eyelet 43.. Probe 12, engages the yarn in loop 2t") and is disposed in a downward position as shown in Fig. 1 with the spring 22 extended and crank section 13 out of contact with electrical contact element 29. if yarn Y breaks, the probe l2 assumes position A, and an electrical contact is established between probe 12 and Contact element 29. it" the yarn Y becomes slack as may occur when the yarn is idle the probe will assume position B shown in Fig. 1 because the yarn will become locked between the fingers 42, 43 of the yarn holder. Vhen the probe is in pc on '3, the crank section 13 cannot make contact with electrical element 2? to complete the associated stop-motion electrical circuit.

in 6 is shown a modified form of yarn holder in which the end of the yarn holder has a deep narrow closed ll-shaped ection d5 which widens into parallel as, f" attached to cover member ll. Under certain conditions such as when the yarn need not be threaded lerally into the yarn holder the modified ,"l holder shown in Fig. 6 may be used.

form of in '7 is shown a gravity operated drop-wire broken yarn dete having a probe 47 which drops to position C re yarn Y breaks. in order to predro i the probe when the yarn is idle and n holders shown in Figs. 5 or 6 may be 7 is shown the yarn holder constructed :lg. 5 with the constricted V-shaped seclt will on 44 so that the probe is held in cannot cause contact between the electrical circuit elements inside the detector housing.

in Figs. 8, 9 are shown a modified arrangement for adjusting the tension in spring 22. One end of spring 22 is attached to the crank section 13' of probe l2.

Cit

The other end of the spring is attached to a looped string or thread 4% which engages the slotted end 55 of a rotatable pin 52. A toothed knob is fitted to the end of pin 5'2. The teeth of knob 51 engage the resilient end of a spring so that as the knob 51 is rotated there is a detent action between teeth 54 and spring 4? which limits rotation of the knob by discreet amounts determined by the distances between adjacent teeth. As the knob 51 and pin 52 rotate, the loop winds up on pin 52 thus varying the tension on spring 22 as desired. A stationary pin 53 attached rigidly to the knob Sl serves as a stop elementfor limiting rotation of theknob when the stop element contacts spring 4 9 Spring 49 projects outwardly through an aperture in the bottom of base member it) and is coiled around the base of pin 52, on the inside of base member iii. Pin 52 rotates freely inside the coil of spring 49 and is limited in its motion only by the detent action between the outer end of spring and teeth 5 of knob 51, and by the contacting of pin 53 with the end of spring The yarn detector as herein disclosed accomplishes all of the objects of the invention and embodies all of the desirable features above mentioned. The probe 12 is designated a l ly-wire because it automatically rises when the yarn breaks as shown in Fig. 1 and is wholly independent of gravity in its movement. The spring 22 which serves to energize the fly-wire probe is adjustable in its tension which is a feature absent in the gravity operated drop-wire detector shown in Fig. '7. Since the fiy-wire is spring loaded, its movement is more positive and may be made faster than is possible with a gravity operated drop wire. The yarn holder embodied in the detector is a very valuable feature which overcomes all danger of closing or operating the stop-motion electrical circuit ii the yarn becomes slack for any reason.

lilthough a limited number of modifications of the invention have been disclosed it will be obvious to those skilled in the art that many modifications and changes are possible without departing from the scope of the following claims for which United States Letters Patent are desired.

I claim:

1. A yarn detector comprising a housing, a wire probe carried by the housing and pivotable thereon, a spring connected at one end to an end portion of the probe, an electrical element disposed to contact the said end portion in one position thereof, said probe having a section bent to engage a movable strand of yarn with the probe held under spring tension, and a yarn holder attached to said housing and having a V-shaped section, whereby the said yarn when slack may be caught in said \.-shaped section, and said end portion of the probe may contact said electrical element when the probe is free from engagement with the yarn, said yarn holder comprising a pair of spring fingers attached at one end to said housing and bent to contact each other to form a substantially V-shaped section with the free ends of said fingers flaring outwardly.

2. A yarn detector according to claim 1 wherein the other end of the spring is connected to an adjustable tensioning device.

3. A yarn detector according to claim 2 wherein the said tensioning device is controlled by a frictionally restrained lever.

4. A yarn detector according to claim 2 wherein the said tensioning device is controlled by a detent limited member.

5. A yarn detector according to claim 4 wherein the detent limited member is a knob with circumferentially arranged teeth engaged with a spring carried by the housing.

6. A yarn detector for knitting machines and the like, said yarn detector being sensitive to a broken yarn but not sensitive to a slack yarn, said yarn detector comprising a housing, a probe pivotally mounted on said housing for engagement with yarn moving in one direction, the pull of the yarn on said probe pivotally moving said probe into one position on said housing, a spring connected to said probe and urging it to pivot in the opposite direction to a second position, an electrical contact member engageable with said probe in said second position, the action of the spring being weaker than the pull of the yarn when the yarn is unbroken and taut, whereby the action of the spring is overcome by the pull of the yarn and the probe is held in its said first position, and a catch situated adjacent the yarn in a position which enables it to engage and hold the yarn when the yarn slackens without breaking and its pull is no longer able to overcome the action of the spring, whereby the probe is caused to pivot toward its said second position, carrying the slack yarn with it into engagement with said catch, said probe being prevented from reaching its said second position by reason of the engagement of said slack yarn with said catch.

7. A yarn detector in accordance with claim 6, wherein one end of the spring is attached to the probe and the opposite end of the spring is attached to an adjustable tensioning device, whereby the tension of the spring may be adjusted in relation to the pull of the taut yarn on the probe.

8. A yarn detector in accordance with claim 6, wherein the yarn catch comprises a pair of spring fingers which are disposed in engagement With each other to resiliently catch the slack yarn between them.

1,835,732 Wachsman 1,845,454 Wachsman Feb. 16, 1932 2,468,611 Arrowood Apr. 26, 1949 

1. A YARN DETECTOR COMPRISING A HOUSING A WIRE PROBE CARRIED BY THE HOUSING AND PIVOTABLE THEREON, A SPRING CONNECTED AT ONE END TO AN END PORTION OF THE PROBE, AN ELECTRICAL ELEMENT DISPOSED TO CONTACT THE SAID END PORTION IN ONE POSITION THEREOF, SAID PROBE HAVING A SECTION BENT TO ENGAGE A MOVABLE STRAND OF YARN WITH THE PROBE HELD UNDER SPRING TENSION, AND A YARN HOLDER ATTACHED TO SAID HOUSING AND HAVING A V-SHAPED SECTION, WHEREBY THE SAID YARN WHEN SLACK MAY BE CAUGHT IN SAID V-SHAPED SECTION, AND SAID END PORTION OF THE PROBE MAY CONTACT SAID ELECTRICAL ELEMENT WHEN THE PROBE IS FREE FROM ENGAGEMENT WITH THE YARN, SAID YARN HOLDER COMPRISING A PAIR OF SPRING FINGERS ATTACHED AT ONE END TO SAID HOUSING AND BENT TO CONTACT EACH OTHER TO FORM A SUBSTANTIALLY V-SHAPED SECTION WITH THE FREE ENDS OF SAID FINGERS FLARING OUTWARDLY. 